Hi Bill,
Interesting presentation! A couple notes:
On the FPGA design for the SDR, a significant amount of the work can be done via Xilinx IP. I think the team has the idea that most of the DSP and hardware would have to be built from scratch in verilog. For almost any design today, many people use the block diagram editor from Xilinx instead of writing their own verilog. Not only are these guaranteed to work but all the driver code is also available in their software platform (Vitis). I've looked into some of the DSP blocks they have available and the list is fairly comprehensive (IIR/FIR filters, FFTs, Freq. Synthesizer to name a few off the top of my head).
One of the other benefits is that many of Xilinx's products have hard integrated processors or have the ability to integrate soft processors (See Zynq and MicroBlaze respectively). The nice thing about these is that they support Linux development and bare-metal/RTOS configuration. We might even be able to remove the TMS570 and replace it with one of the multi-core devices. Perhaps we could have a system where Direwolf and the other processing functions are run on the same chip as the DSP. The downside to this is that I'm not sure how parallelable that would be (i.e. could we maintain four Rx channels).
I do a lot of work with Xilinx products and FPGAs at work. It's mostly for video functions, but I've found it pretty easy to understand the fundamentals of Vivado/Vitis in only a few months. With integrated peripherals like AXI and the IP blocks, it probably wouldn't take as long as everyone is thinking. I hardly ever touch verilog at work anymore...
As far as the amplifier project is coming, I'm back in the lab at work and want to get some more prototyping done with our actual amplifier. Does anyone on the team have extra stock of the transistor we're using for the Tx amplifier (ATF05MS004NT1)? I'd also like to get an inductor kit like
this one as the one I have at work is all 0201s and I can't reliably solder it...
On that note, I'm happy to keep prototyping it if the team wants to go in that direction, but I think it'd be faster to go with a premade power amp. I've already created a schematic for a PA as a backup to the work I'm doing now. If we want something for Jim's test board, I could probably get something to at least prototype with a lot sooner even if we think we could do better with the discrete option. Just a suggestion.
Thanks,
Cameron Castillo
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Cameron Castillo
KJ7ILB
P: (503) 752-8877
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